The invention relates to a panel for closing an opening, with a panel element and a clip system for clamping said panel element against a rebate of the opening, comprising at least one bolt which is movable between a first position for clamping the panel element against the rebate and a second position for releasing the panel element, and an operating mechanism for moving said bolt.
Such a panel is known as a "clip door", which is used in ships for closing passages in walls and partitions of the ship. An important requirement of such a panel is that it should be able to close the passage reliably and in a watertight manner. For this, the panel element can be clamped against the rebate, and a flexible sealing section is clamped between the edge of the panel element and the edge of the passage.
The bolt and the rebate are designed in such a way that the panel element is clamped against the rebate when the bolt is moved from the first to the second position.
For this, the bolt in the known clip door swivels about an axis at right angles to the plane of the panel element, and the bolt and the rebate are provided with clip surfaces running at corresponding angles relative to the plane of the panel element or of the wall in which the passage is provided. When the bolt is moved from the second to the first position, said clip surfaces knock against each other and are pushed along each other, so that the panel element is clamped against the rebate.
A disadvantage of this known panel is that operation of the clip system requires great force.
The problem of the great force required to operate the bolt is further aggravated in panels with several bolts which are provided with an operating mechanism for operating at least a number of the bolts, in order to ensure that said bolts are always operated when the panel is being closed.
An example of a panel with an operating mechanism for operating several bolts is the so-called coupled clip door, in which one of the bolts is firmly connected to an operating mechanism, and that one bolt is coupled to other bolts, so that they can be operated simultaneously by the operating mechanism. Operation of the clip system of such a panel requires extremely great force. Furthermore, the coupling mechanism requires a great deal of maintenance, in particular as regards lubrication, otherwise operation of the system takes such force that the door can no longer be clamped properly against the rebate.
In another example of a panel with an operating mechanism for operating several bolts, the so-called central clip door, the door is provided with a central operating mechanism with a reduction, which is coupled to several bolts. The operating mechanism is in this case in the form of a hand wheel coupled to the reduction which comprises a gear wheel with a smaller diameter than the hand wheel and a gear rack. The gear rack is in turn coupled to the bolts. This door requires less force to operate the operating mechanism than in the case of the coupled clip door. Disadvantages of a central clip door are, however, that the operating mechanism is an unwieldy, expensive construction with a great mass, turning the hand wheel requires several actions, it cannot be seen from the position of the operating element whether or not the door is closed, and the operating mechanism has to be regularly inspected and overhauled.